I just bought the rogue morimoto soba ale and mashed it like any other grains... The "how to" pamphlet didn't say anything otherwise for the buckwheat.
Edit: I do believe they were cracked though.
A clone recipe from member T-West:
WYeast American Ale (I got WYeast Northwestern Ale for my kit, a Pacman like yeast, Rogue's proprietary yeast.)
OG/ FG: 1.048/ 1.016 (soba has lots of unfermentables)
5 Gal batch
3lbs Amber DME
1.5lbs Gold DME
.5lbs Pale 2-Row
.5lbs Crystal 15L
1oz Crystal (60 min)
1oz Crystal (15 min)